BAT 



or pool, deftincd for the ufe of thofo who willied to cser- 

 cifc thenifL-lvcs in fwimmiii^. 



In front, on the right and left, were other baths for peo- 

 ple of fuptrior confequence. In the room of bafons they had 

 large bathing velTcIs, which were of copper, porphyry, 

 granite, or bafaltes. They alfo contained feats of marble 

 or porphyry ; of which we yet fee a great number at Rome. 

 Olympiodoriis aflures us, that the baths of Caracalla had 

 jin kfs than lixteen hundred. 



The grand hall was a rotunda, ill feet diameter ; which 

 is believed to have been called cdla fnleans, or the hall ot 

 fandals, of w'liicU Spartianus fpeaks in thefe terms: " Cellam 

 folearem architedli negaiit pufle uUa iniitatione qua fafta efl: 

 fieri." It feems to have had its name from the bars of 

 copper and bronze which, according to fome, formed its 

 pavement, and to others its cieling ; bearing fome refem- 

 blance to the fatlening of the fandals among the ancient 

 Romans. It had alfo la\ge plates of bronze or copper, 

 which covered and oni.imented the piers of the windows and 

 other parts of the rotunda. It contained a number of veiTels 

 in which the warm bath waj taken. 



Of ail that relates to the baths, notiiing has fo embarraffed 

 the learned as the manner in w(hich hot wat^'r was fupplied 

 to all the receptacles for bathing which have been found. 

 For if we fuppofe, and it mav be done without exaggera- 

 tion, that each batii in the thermre of Dioelefinn was capa- 

 ble of containing fix batliers, 1800 perfons mi.;ht have 

 bathed at once. But as no veftige remains, fuincient to 

 favonr our conjectures as to the manner in which the water 

 paffed into thefe veiTels, we mull content ourfelves with what 



Vitruvius has faiJ upon it Baccius has treated this fubjedl 



better than any of the moderns. He imagines the water was 

 conveyed from rcfervoirs outfide the thermre, and that 

 machines were ufed for raifing it to that height, which, 

 agreeably to his examination of Dioclefian's baths, feemed 

 requifite. He was alfo induced to conclude, that the water 

 was heated outfide the thermx, from the number of pipes 

 which he faw underneath the area of the building ; where 

 there had never been > any alteration, and which were all 

 furronnded by other pipes from the hypocauft. But this 

 fuppofition appeared to Baccius hinifelf fo replete with 

 difficulties, that he pufhed his refcarches on this matter no 

 farther. 



The two figures of the water towers or rcfervoirs for the 

 baths of Caracalla, engraved by Pirancfi, will fufiice to ex- 

 plain hov7 cafily the Romans heated the largcfl body of 

 water their thermx could contain. 



The water tower of Caracalla received its fupply from 

 the aqueduft of Antoninus, part of which pafTed by the 

 Appian way. 



It appears from the plan of this refervoir, that it had, 

 immediately above the hypocauft, twenty-eight vaulted 

 chambers ; that thefe chambers formed two ranges of 

 fourteen each ; and that they had a communication one 

 with the other. Above tliefe were twenty-eight other 

 chambers, which were connctted with each other in like 

 manner, though only one of them communicated with the 

 chambers below. Above all thefe was a fpacious refervoir, not 

 very deep, but whicli extended the whole length of the water 

 tower ; i.i this, the water received confiderable v.-armth from 

 the heat of the fun, before it paffed into the chambers. 

 This refervoir did not receive its water direcfly from the 

 aqueduct, but from an intermediate cillern. Whenever it 

 appeared necetfary to draw off the water of the lower 

 chambers to fill the bathing places, the water of the refer- 

 voir became ufelcfs, and would have overflown but for an 

 opening on one fide of the cillern, by which it efcapcdwilh- 



BAT 



out going into the baths. Dming all this time the water 

 of the rcfervoirs was tranquil. The cillern anfwered two 

 purpofes ; it prevented any agitation in the water of the refer- 

 voir, and carried off that which was of no ufe. When the 

 twenty-eight vaulted chambers, immediately above the hypo- 

 caull, began to heat, the warmth they acquired was quickly 

 augmented ; as there was only one of them wliich commu- 

 nicated with the exterior air. 



The flrcngth of the walls and vault was quite fufRcient to 

 refill the rarefaction of air within the water, a;id of confe- 

 quence to hinder its evaporation from producing danger. 

 It was ncceirary that it fliould have pipes to give the v.atcr 

 a fufficient heat for the ufage of the bath. When the hour 

 of baching came, the warm water was let into the bathing 

 places from the lower chambers ; where it ran with incredible 

 fwiftnefs, and rofe to a perpendicular height equal to the lur- 

 face of the refervoir of the water tower. 



To hinder the wat?r from cooling as it paffed tlirough the 

 fubterranean pipes, thev were inclofed in others which came 

 from the entrance of tlie hypocauft, forming a fort of double 

 tup.nel, and acquiring a confiderable degree of heat befoie 

 the water entered them. 



Each chamber was within the walls 49 feet long, 27 wide, 

 and about 30 high. The number of fquare feet on the furface 

 of the lower cliamber amounted to 38,500. If we allow for 

 the medium height 30 feet, the quantity of water contained 

 ill the lower chambers amounted to 1,143,450 cubic feet. 



The ancients do not inform us how they difcovered the 

 method of heating fuch large volumes of water. We are 

 therefore in the dark whether it was an invention of the 

 Romans, or whether they brought it with them from the 

 Eaft. It is reafonable, however, to fuppofe, that fuch 

 methods could be of no ufe before the conftruftion of the 

 therniK at Rome, and of courfe could not be older than 

 the time of Auguilus; in whofe reign, Dion CafTius informs 

 us, Mxcenas built a warm bath capable of admitting per- 

 fons to fwim in. 



This method, or one very fimilar, was ufed in all the baths 

 of Rome. That defcribed by Vitruvius was infufficient to 

 furnifli water for thefe vafl buildings, which Ammianus 

 Marcellinus compares to provinces (lavacra in modum pro- 

 vinciarum extrucla) ; though it \ras undoubtedly the cafe in 

 private baths. They heated the water of the bath, fays 

 Vitruvius, by means of three veffcls of copper, fo difpofed 

 that the water flowed from one to the other. One was 

 called caldarium, another tepidarium, and the third frigida- 

 rium. The marquis Galiani obferves, that it is no eafy matter 

 to give a precife idea of the fituation of thefe vafcs above 

 the furnace. Casfariano and Caporali have engraved one 

 above the other, or rather one within the other, placing the 

 frigidarium above the tepidarium, and that above the cal- 

 darium, which was placed immediately above the furnace. 

 But the great difficulty is, that in this arrangement the heat, 

 by the afcenfion of the flame, ought to warm the upper vafe, 

 or frigidarium. Perrault, on the contrary, places the three 

 vafes on a level ; and he imagines that fyphons carried the 

 water of one vafe into another : but how, without a piilon, 

 or fome fucli expedient, the water could be railed fo as to re- 

 defcend, he has not explained. 



The ancient paintings of Titus's baths place thefe vafcs 

 upon three fteps, in fuch a manner that the bottom of the 

 water of one veflel fhall be upon a level with the aperture of 

 the other ; fo that it is eafy to comprehend how the water 

 • was conveyed. But the marquis Galiani believes, that this 

 difpofition is not altogether agreeable to the trutli ; and that 

 it was adopted by the painter, only to afford a more clear idea 

 how the water was transferred. 



I believe. 



